Variations in serum levels of interleukin (IL)-1beta, IL-2, IL-6, and tumor necrosis factor-alpha during specific immunotherapy.

BACKGROUND

Cytokine production by T helper cells is essential for the induction and maintenance of allergic inflammation in the bronchial mucosa. According to recent views, specific immunotherapy (SIT) favors the differentiation of T lymphocytes into cells of the Th1 rather than those of the Th2 subset.

OBJECTIVE

To determine whether or not SIT induces a decrease in the inflammatory reaction by studying eventual variations in the serum levels of IL-1beta, IL-2, IL-6, and TNF-alpha in allergic subjects during SIT.

METHODS

Serum levels of IL-1beta, IL-2, IL-6, and TNF-alpha were determined before and after 3, 6, and 9 months of SIT by an immunoradiometric assay (IRMA) in 11 adults with perennial allergic asthma and/or rhinitis caused by house dust mites and in 6 nonatopic healthy volunteers.

RESULTS

Median serum IL-1beta and TNF-alpha levels of the patients were significantly higher at baseline than those of the controls and decreased during SIT to values similar to or lower (P < .01) after 6 months of SIT for TNF-alpha than those of the controls. Median serum IL-2, significantly lower at baseline than in the controls, increased during SIT to a level similar to that of the controls. Although the median values of IL-1beta and TNF-alpha in the patients tended to decrease and those of IL-2 to increase during SIT, the differences were not significant; the correlation coefficients (r) of the serum levels of IL-1beta IL-6, and TNF-alpha versus duration of SIT were negative, while that of IL-2 was positive.

CONCLUSIONS

Decreases in median serum IL-1beta and TNF-alpha levels during SIT, together with the increases in serum IL-2 and IL-6, compared with those of the controls furnish evidence supporting a reduction in the inflammatory response in the course of SIT.